West Midlands slang word for rockers, bikers, greasers etc. In the late 1980s it was used by the UK music press to refer to a specific scene centered around the bands Pop Will Eat Itself and Crazyhead. The term never found favour with readers of 'the inkies' (Sounds, Melody Maker and the still extant NME) and was soon dropped. Now often used in predominantly working-class areas of the midlands and the north to mean someone who listens to rock-derived music and/or dresses in a manner that suggests they affiliate themselves with rock music of some kind.

Some grebo passed with Sabbath playing on his stereo.
The Poppies are at no. 17? God, a grebo band in the charts!
They're playing nu-metal now, bloody grebos!

A grebo is a commonly used term for people who follow an 'anti-pop' culture. The grebo's archenemy is the townie; grebos generally prefer to wear baggy, darker clothing as well as simple metal jewelry to reflect their darker, anti-pop lifestyle. Most grebos will listen to Slipknot or any other number of popular nümetal bands such as Disturbed.

The contradiction of the Grebo is that through their anti-pop mantra they have effectively created a subculture much like the one that they have rebelled against; it is one that exists to defy the opposite of what pop culture is, and still has its own subcultural standards in wardrobe, music, speech, etc., making the Grebo subculture somewhat pretentious, yet more open to social outcasts or socially unaccepted / otherwise politically incorrect schools of thought or action.

Look at those Grebos, listening to Slipknot. Don't they see that through their rebellion they have built nothing much greater than the culture they have rebelled against?

1: A word used by chavs/trendies to describe anybody who is not a chav or a trendy. These include goths, skaters and any other form of identity.
2: Another word to describe a punk
3: Someone who listens to Green Day

"Dude, you have baggy jeans, you got rid of your baseball cap, you listen to Green Day - your a totaly grebo!"

people that rock, no doubt about it. they put up with 'townie' idiots shouting abuse such as 'uh u dirrty fuckin grebo, u watch' and then running off and never doin anything about it. they listen to decent music, like rock, metal, punk, etc. no pop crap. they usualy wear darker clothing, and dont follow any stupid trends, like townies do, and dont try hard to fit in, most grebos will accept anyone aslong as there not a complete prick. yeah, grebos rock

when used here in (h)ull it means any one whos into metal, nu-metal or industrial.
Although in secondary school it also means any mini-mosher whos got a taller mohawk or longer hair than overs.
Only ever used by townies, tegs, tards, or trendies trying to look hard! (the clue is in the 'T's)